1. Field of the Invention
The present invention is broadly concerned with an improved, low cost method and apparatus for producing comminuted meat products such as patties with the complete elimination of conventional casings typically used in patty formation. More particularly, it is concerned with such a process and apparatus wherein an elongated, preformed, uncased, peripherally unrestrained, generally substantially uncooked comminuted meat body is first crust-frozen to render the body substantially shape-retaining, followed by transverse slicing to yield patty products.
2. Description of the Prior Art
Comminuted meat products such as hamburger and sausage are often produced and sold in the form of patties, in order to facilitate handling and cooking by the ultimate end user. Typically, such patty products are produced by directing the comminuted meat into and through a stuffing horn, where the meat is encased in a skin or synthetic resin casing or an open-ended "slick", all such expedients being referred to herein as "casings." Thereupon, the encased meat is either partially or completely frozen, followed by a tempering step to put the meat in the optimum condition for slicing. Finally, the casing or slick is removed from the frozen/tempered meat, and the product is sliced to obtain the desired patties.
This type of process is quite conventional and of long standing. However, it is relatively expensive and cumbersome, because of the need to initially encase and seal the meat, followed by a freezing/tempering cycle.
An alternate process is described in U.S. Pat. No. 2,670,296. In this process, ground meat is initially extruded into an elongated block which is completely frozen to a temperature of from 10.degree. to 25.degree. F. below zero. At this point, the block is sliced to yield the desired patties. The process of this patent is deficient in that it contemplates complete freezing of the meat blocks, which can be time-consuming and expensive. By the same token, experience has shown that attempts to slice fully frozen meat bodies can be difficult and lead to shattering of the meat. Indeed, this is the very reason why conventional casing methods employ a tempering step prior to slicing.
It has also been suggested in the past to partially freeze whole muscle meat products such as pork loins, followed by cutting or slicing. However, even in these processes, the whole muscle products are typically pressed and formed during the slicing operation. Thus, U.S. Pat. No. 3,852,507 describes a process wherein an irregular meat mass is formed by a die mechanism into a predetermined shape while the meat is partially frozen. Such pressing and the resultant peripheral restraint on the meat tends to cause undue compaction, however, and the resultant sliced product may exhibit undesirable organoleptic properties.
U.S. Pat. No. 3,926,080 describes a method for processing whole muscle products such as pork loin by initial crust-freezing in liquid nitrogen, followed by severing of the loin into chops. This reference does not suggest or intimate, however, any method for forming comminuted products such as hamburger or the like using a crust-freezing technique.
Other references describing various meat forming methods include U.S. Pat. Nos. 4,258,006, 4,268,532, 4,372,734, 1,943,019, 2,397,446, 2,521,849, 2,641,797, 3,421,434, 3,851,355, 3,889,013, 4,068,008, 4,205,415, 4,349,575, 4,530,132, 4,539,210, 4,544,560, 4,060,998, and 3,108,883.